Assert a claim

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

Annotations declare a non-read-only, non-destructive, closed-world write, and the description goes beyond them: it discloses that only evidence existence and project ownership are validated, that semantic support is deliberately NOT checked, and that evidence is embedded for auditability. It omits idempotency/duplicate handling and error behavior for a mutation tool, which keeps it from a 5.

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?

Three sentences, front-loaded with the action and payload, then the scoping negations and the auditability rationale. Every sentence earns its place, though the 'that would be interpreting' aside and the final clause slightly pad an otherwise tight definition.

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 an output schema available, return values need no explanation, and the description covers the write semantics and validation boundary well for a 6-parameter mutation. Remaining gaps are minor: no statement on duplicate/conflicting claims or on what happens if the referenced evidence 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 the schema already documents every parameter including the observed_at derivation rule and the evidence union. The description restates the field set without adding format, syntax, or constraints beyond what the schema provides, which is the expected baseline here.

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 ('Write a claim into the project registry') and enumerates the payload fields. The explicit negations ('does NOT measure anything') separate it from the facts.measure.* siblings, so an agent can distinguish it without opening other schemas.

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 description draws a clear boundary: use this to record a claim, not to measure and not to interpret evidence. It does not name any alternative tool (e.g. facts.recall.query for reading) or state prerequisites, but the when-not conditions are explicit enough to route correctly.

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