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

Annotations already establish read-only, idempotent, non-destructive semantics, so the description's job is lighter. It adds genuine behavioral value beyond the annotations by declaring sort order ('Newest first') and that the response is an index with no narrative prose ('No prose'). It does not mention pagination behavior despite the limit parameter.

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 front-loaded with the core purpose, then the returned shape, then the downstream-tool relationship, then two short trailing facts. Nearly every clause earns its place, though the field enumeration is dense and 'Newest first' reads as a tacked-on fragment.

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 carries the burden of describing return values, and it does so thoroughly (field list plus per-document links). Annotations cover the safety profile, and parameters are largely handled by the schema. The remaining gap is pagination/limit behavior, which an agent would need for iterating large result sets.

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 coverage is 83%, so the schema already documents limit, since, symbol, ticker, doc_types, and identifier, making the baseline 3. The description's only parameter-relevant contribution is implicitly mapping 'concall transcripts, annual reports, presentations, IPO documents' to the doc_types enum, which adds marginal meaning beyond the schema.

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 clearly identifies the resource ('Index of a company's filings parsed to text') and enumerates exactly what it returns (doc_id, type, period, date, num_pages, flags, links), so an agent knows it is a listing/retrieval tool for corporate documents. It relates itself to get_document_summary and read_document by noting the doc_id feeds those tools, which aids disambiguation. The only weakness is that no explicit verb is used ('Index of...' rather than 'Lists...'), but the intent is unmistakable.

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 sentence 'The doc_id is the input get_document_summary and read_document take' effectively tells the agent this is the discovery step in a two-stage workflow, which is meaningful usage context. It does not, however, provide explicit when-to-use vs when-not guidance or exclusions, so it stops short of full routing clarity.

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