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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful context about ZIP-level availability ('where the site publishes one') and clarifies the data source (city permit value vs price paid). However, it doesn't disclose behavior like missing data handling, date ranges, or response format, which would be valuable for a data lookup tool.

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 compact and front-loaded: it states the core output (median and middle half of job value, permit count, dates) in the first sentence, then clarifies the ZIP behavior and the value definition. Every sentence earns its place, and there is no redundant repetition of schema details.

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 read-only lookup tool with 100% schema coverage and no output schema, the description covers the key aspects: what is returned, how ZIP filtering works, and the definition of the value. It could mention what happens when no data exists for a city/kind_of_work combination, but overall it is sufficiently complete for an agent to invoke it 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 schema already documents all three parameters. The description adds meaning by explaining that zip is optional and only used where the site publishes a ZIP-level figure, and that kind_of_work refers to the permit's stated work type. This is helpful but not extensive; the schema already carries the parameter definitions.

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's purpose: it returns the job value stated on city permits for a given kind of work, with median and middle half statistics, permit count, and dates. It distinguishes itself from siblings by focusing on permit value statistics rather than timelines, contractors, or estimates.

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 explains that a ZIP is needed to get a ZIP-specific figure where the site publishes one, and clarifies that the value is the city permit's stated value, not the price paid. It doesn't explicitly name alternatives or when-not-to-use, but the context is clear enough for an agent to select this tool for permit value queries.

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