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

Annotations already declare the read-only, idempotent, non-destructive, open-world profile, so the bar is lower; the description still adds real behavior: the returned field set, the default sort, and the non-obvious cap of '30 best keyword matches when a keyword is given'. It omits rate limits and pagination behavior, keeping it short of 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?

Three tightly packed sentences, front-loaded with purpose and scope before return details and caveats. Dense but nearly every clause carries new information; slightly long, which keeps it from a 5.

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?

No output schema exists, and the description compensates by enumerating returned fields (title, opportunity number, agency, dates, award floor/ceiling, eligibility types, link) and the default ordering. For a read-only, zero-required-parameter search tool this is sufficient to call correctly.

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 the baseline is 3. The description adds meaning beyond the schema with the hidden 30-match keyword cap, the default sort rationale, and the warning that eligibility codes must be confirmed against full announcements.

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 ('Search ... US federal grant opportunities on Grants.gov') plus the dimensions searched (keyword, eligibility, category, agency) and the source scope. It is clearly distinguishable from get_grant_details (single-grant lookup) and list_grant_filters (filter enumeration).

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?

Explicit when-to-use ('when the user wants to find federal grants for an organization, project or topic'), explicit when-not ('not state, local, foundation or corporate grants'), and it routes to an alternative ('always confirm eligibility with get_grant_details'). The schema additionally points to list_grant_filters for agency codes.

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