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

The readOnlyHint annotation already signals safety, and the description adds meaningful behavioral context: it aggregates every matching award and returns totals rather than a page of records. It also discloses that filters are shared with search_awards, giving the agent useful expectations about match semantics.

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?

Two sentences carry all essential information: grouping dimensions, computed metrics, usage example, and the distinction from paginated search. Nothing is redundant and the key behavior is front-loaded.

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 an aggregation tool with no output schema, the description compensates by listing the computed fields and grouping options. It could be more explicit about result ordering, the meaning of 'share,' or the cap on returned groups, but the combination of title, schema, and description is adequate for correct invocation.

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 schema already documents all nine parameters. The description adds a light semantic link by saying filters match search_awards, but it does not meaningfully deepen understanding of individual parameter formats or edge cases 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 uses a specific verb ('Aggregate') and names the exact resources and grouping dimensions: recipient, resolved ticker, or awarding agency. It also lists the output metrics (count, dollars, share, first/last, largest) and distinguishes itself from search_awards by clarifying it counts all matches rather than returning a page.

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 description gives a concrete query example ('who won the most from the Navy this year') and explicitly notes this tool counts all matches, not a page, which signals when to choose it over a record-returning tool like search_awards. It does not explicitly name when-not-to-use or fully contrast with sibling aggregation tools like pac_totals.

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