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

Annotations already declare readOnly, idempotent and closed-world, so the safety profile is covered. The description adds genuinely useful context beyond them: an Enterprise Data key is required, passed as an X-API-Key header, with a documentation link — an auth gate an agent would otherwise only discover on failure.

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, both load-bearing, with the data scope front-loaded ahead of the auth prerequisite. Minor redundancy in the parenthetical URL fragment, but no filler prose.

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 usefully previews the returned fields, and it flags the auth requirement — the two things an agent most needs. Pagination and ordering behavior go unmentioned, though the `page` parameter in the schema mitigates that gap.

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 every parameter, including the derived `id` and the `ends_before` pattern, is already documented in the schema. The description restates the returned fields but contributes no additional parameter meaning, which is the baseline-3 case.

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 resource retrieval: all contract rows of one supplier, naming the fields carried (buyer contact, end dates, amounts). It is clear what the tool returns, but it never names or contrasts the many overlapping siblings (assay_contract, assay_line_contracts, assay_ending), so an agent must infer the boundary itself.

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?

There is no when-to-use or when-not-to-use guidance and no alternative named, despite a dense sibling set of contract-related tools. The only conditional statement is a hard prerequisite (Enterprise Data key), which is access guidance rather than selection guidance.

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