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

Annotations already cover safety (readOnly, non-destructive, closed-world), but the description adds meaningful process semantics: the latest annual report sets the baseline, interim reports and event disclosures update existing durable instrument records rather than spawning look-alike duplicates, and unmatched observations are disclosed and excluded. That is real behavioral context. It stops short of describing pagination limits or ordering of returned instruments.

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 resource and routing, then the caveat about unmatched observations. Dense but each sentence carries distinct information. Slightly jargon-heavy ('durable instrument records') but not padded.

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?

No output schema exists, and the description adequately explains what comes back: a summary per instrument plus its ID, with unmatched observations excluded and disclosed. Combined with annotations covering safety, an agent has enough to call it correctly, though paging behavior across the many offset parameters is left to the schema.

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 fully documents offset, maxResults, evidenceOffset, and the reported-total paging controls. The description adds no parameter-level detail (no paging semantics, no guidance on maxEvidenceCharacters). Baseline 3 is appropriate 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 plus a precisely scoped resource set: 'source-linked reported debt balances, total debt history, and identified notes, loans, and revolving credit facilities.' It also explicitly contrasts itself with the closest sibling (GetDebtInstrument), so an agent can discriminate without opening 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?

Names the alternative (GetDebtInstrument) and the conditions that select it: paged covenants, filing observations, exact evidence, governing SEC exhibits. That is clear routing guidance. Minor ambiguity remains because this tool itself exposes evidence paging parameters (evidenceOffset, maxEvidenceCharacters), so the boundary around 'exact evidence' is not fully crisp.

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