FactStamp

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations cover the safety profile (readOnly, idempotent, openWorld), and the description goes well beyond them: it names the upstream data sources, discloses the four possible outcome states (found/ambiguous/not_found/unknown), and states the key matching guarantee that a near name match is never reported as a match. That is exactly the behavioral context an agent needs to interpret results.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the verification question, then the evidence basis, then the result taxonomy. Dense and largely waste-free, though the final negation list reads as a run-on and could be tightened; nothing is buried, so the cost is small.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description compensates by enumerating the possible return statuses and the sources behind them, and it bounds scope with explicit non-goals. For a two-parameter, read-only lookup, nothing an agent needs in order to call or interpret it is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so both parameters (query, jurisdiction) are already fully documented, including the identifier-exactness rule. The description's reference to 'under which identifier and jurisdiction' adds only framing, not new syntax or format detail. Baseline 3 applies when the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Verify a legal entity') and enumerates the exact questions answered: existence, identifier/jurisdiction, and registration currency. The closing scope exclusions ('not advice, not a credit check, not a sanction screen') separate it from adjacent verification-shaped tools, so an agent can place it without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The three 'not X' clauses give explicit when-not boundaries, and the cited sources (GLEIF LEI index, US SEC EDGAR) tell the agent what domain of entity this covers. It does not, however, name any sibling tool or state a positive triggering condition beyond the implied verify-an-entity case, so it stops short of full routing guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover the safety profile (readOnlyHint, openWorldHint, idempotentHint), and the description adds real behavioral value: it discloses the four possible return states and that results are cited to the publisher's series with an as-of date. No output schema exists, so this return-shape disclosure is genuinely load-bearing.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Four short sentences, zero waste, front-loaded with the action and outcome vocabulary before the usage cue. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description correctly carries the return-value burden by naming the four statuses and the citation behavior. Combined with 100% schema coverage, an agent has what it needs; only minor operational detail (e.g., latency or rate limits) is absent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so both parameters (claim and series_id) are already documented with examples and routing guidance. The description adds no parameter-level detail beyond the schema, making the baseline 3 appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific action (submit a dated figure claim for verification) and enumerates the exact outcomes (verified, stale, contradicted, unknown) with provenance (publisher's own series plus as-of date). The 'figure' resource implicitly separates it from the sibling check_entity, though no sibling is named explicitly in the description text.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

'Use before committing a number to a page, deck or decision' gives a clear triggering context, and 'Not advice' scopes the tool's role. It stops short of stating when-not-to-use or explicitly naming alternatives like route_claim or list_series, which appear only in the schema.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is covered. The description adds 'Free' as cost context and references an opaque 'no-guess rule,' which is some extra behavioral information but remains unexplained and limited.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is very short, but it is poorly structured: it opens with 'Free.' and then presents a fragment rather than a front-loaded action. The phrase 'no-guess rule' is undefined, so not every element clearly earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-parameter list tool with annotations covering safety and no output schema, the description should at least clarify return shape and when to call it. It names some returned fields (publisher, as-of date) but leaves the no-guess rule and sibling usage unexplained.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters and schema description coverage is 100%. Per the rubric, the baseline for no parameters is 4; there is no parameter semantics for the description to add.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description is a noun phrase listing return contents rather than a clear action; it largely restates the title 'List what this engine covers' without explicitly saying it lists series. An agent can infer from the tool name, but sibling differentiation is absent and the purpose remains vague.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is given on when to use this tool versus check_entity, check_figure, or route_claim. The only contextual clue is 'Free,' which describes cost, not usage conditions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover the safety profile (readOnly, idempotent, openWorld), so the bar is lower. The description still adds meaningful context beyond them: the cost model ('Free', 'pay for check_figure') and the explicit non-outcome ('Returns NO verdict'), which prevents the agent from misusing the result as a judgment.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences; the pricing note is front-loaded as a one-word hook, followed by the output contract and the explicit exclusion. No sentence is wasted and the ordering prioritizes what the agent needs first.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description must carry the return contract, and it does: series, extracted value, date, and signals. It does not cover failure modes or input limits (4000 chars, min 4), but for a single-parameter read-only tool the picture is nearly complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Only one parameter, and schema description coverage is 100%, so the schema already documents 'claim' fully. The description adds nothing about the claim's syntax or constraints, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (route) and resource (claim) plus the concrete output: target series, extracted value and date, and scoring signals. It also explicitly distinguishes itself from the sibling check_figure by declaring it returns no verdict.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicit when-to-use vs alternative: this tool is free and returns no verdict, so the agent is told to call check_figure when a verdict is actually needed. The selection condition is stated outright rather than implied.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.