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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the bar is lower, yet the description adds real context: the subject is read first so an unreadable id returns not-found, the fetch requires the reports scope with the same key, and no document is generated. It does not cover rate limits or return volume, keeping it below 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?

The purpose is front-loaded and each sentence carries information (subject mapping, id sources, auth, no-generation). It is a single dense paragraph with some convoluted phrasing ('the registry id company_profile speaks'), so it is efficient but not maximally readable.

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?

For a 2-parameter read tool with full schema coverage and rich annotations, the description covers subject semantics, id provenance, auth scope, and error behavior. Since there is no output schema, it correctly hints at the return shape ('returns each document's /v1 path'), though more detail on the response structure would fully close the 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 coverage is 100%, so the baseline is 3, but the description adds genuine meaning: it maps each subject enum value to the origin of the corresponding id (deal_book id, registry id, graph node id). This goes beyond the schema field descriptions, though it does not document id formatting edge cases.

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 states the concrete output (the /v1 download path for each PDF document of a subject) and enumerates the three subject types with what each yields (deal report+committee pack, counterparty report+pack, company profile). It is clear, though the opening phrase 'Where to download' reads slightly like a URL helper before the 'returns each document's /v1 path' sentence clarifies it and it does not name any sibling tool.

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?

It gives the use context (filing documents into a library such as SharePoint) and, usefully, tells the agent where each id comes from (deal_book, company_profile registry id, search_companies graph node). It stops short of naming alternatives or exclusions, so it is clear context without explicit when-not guidance.

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