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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering the safety profile. The description adds valuable behavioral context beyond that: the ranking behavior (sorted by unserved/underserved population), the data vintage (FCC Form 477 as of June 2021), and the limit of 50 geography IDs with the compare_all_states override. These are useful and non-contradictory.

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 description is front-loaded with the core purpose in the first sentence, then adds a use case, parameter notes, and data source in a logical order. Every sentence earns its place, with no filler or repetition. It is concise and well-structured.

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?

Given that an output schema exists (as indicated by context signals) and all parameters have rich schema descriptions, the description covers all necessary operational details: what it does, how to use it (with limits), and the data source. 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 description coverage is 100%, so the baseline is 3. The description repeats some parameter guidance (e.g., 'up to 50 geography IDs' and 'compare_all_states=true for all 50 states + DC'), but these are also present in the schema descriptions. It does not add meaning beyond what the schema already provides, so no bonus is warranted.

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 clearly states the tool 'compares broadband coverage metrics across multiple geographies of the same type' and returns a ranked table, which is a specific verb-resource pair. It also gives a concrete example question. However, it does not explicitly distinguish itself from sibling tools like fcc_get_coverage_summary or fcc_find_underserved, so it stops short of a 5.

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 provides clear context for when to use this tool: to answer 'which counties in this state have the worst broadband access?' and for BEAD funding prioritization. It does not mention when not to use it or name alternative tools, so it meets the bar for 'clear context, no exclusions' rather than explicit when/when-not guidance.

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