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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), yet the description adds substantial context: no paging, ID stability across calls with daily field refresh, rate limits tied to the caller's key plan, and an explicit prompt-injection warning about untrusted scraped fields. That is behavior an agent cannot get from the annotations alone.

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?

It is a dense single paragraph but front-loads the core purpose and then layers constraints; nearly every clause carries actionable information. The one minor cost is length, but no sentence is redundant.

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 compensates by describing the return shape (single object, no paging, named fields) and error semantics. Combined with the annotation-covered safety profile and a one-parameter 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?

Schema coverage is 100% and already defines contract_id as a UUID with a regex pattern, so baseline is 3. The description goes beyond the schema by stating the id must originate from a search_contracts result and that malformed ids are rejected before the request, adding usage semantics the schema cannot express.

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 full details for a single government contract by ID') and enumerates the returned facets (agency, set-asides, NAICS codes, dates, attachments). It clearly contrasts with the list-oriented sibling search_contracts by specifying 'a single' contract and 'returns one object, no paging'.

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?

Explicitly tells the agent where the required id comes from ('Take the id from a search_contracts result'), routing it to the correct sibling. It also sets expectations for failure modes (non-UUID rejected pre-request, unknown id returns an error not an empty object), leaving little to inference.

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