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

Annotations already cover safety (readOnly, idempotent, non-destructive), and the description adds real behavioral detail on top: ambiguity produces an error listing the matches, out-of-coverage produces an isError, records come back reviewed and unreviewed with tier, and filings are capped at 5. The 'not monitored is not zero' caveat is an important interpretive warning that no annotation or schema conveys.

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 verb and resource, and every clause carries information the agent needs (accepted identifiers, payload sections, both error modes, the not-monitored caveat). It is a single very dense sentence, though, and could be broken for scanability without losing content.

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?

Output schema exists, yet the description still summarizes the payload shape well enough to inform selection, and it covers both error paths an agent will actually hit. For a one-parameter lookup with annotations and an output schema, nothing an agent needs to call it correctly 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?

With a single parameter and 100% schema description coverage, the schema already documents that name_or_id accepts name, CIK (leading zeros optional), or slug, including an example. The description restates the same identifier list without adding format, normalization, or precedence rules, so the baseline of 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 and resource: 'Get one covered company' plus the four accepted identifier forms, and enumerates the payload (identity, dossier status, coverage statement, records, filings). It is clear enough to distinguish from list_companies and search_records, but it never explicitly names a sibling or draws the boundary with get_coverage/get_filings_wire, which return overlapping data.

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?

Usage is implied by the identifier forms ('by name, former name, SEC CIK or slug') and the failure modes: an ambiguous name errors with a list, and out-of-coverage errors with isError. There is no explicit when-to-use-vs-alternatives guidance telling the agent to prefer this over search_records when the exact entity is unknown, so the routing is left to inference.

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