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

Annotations already declare readOnlyHint/idempotentHint true and destructiveHint false, so the safety profile is fully covered by structured data. The description does add return-value semantics (percentiles, sample size, honest regional/UK-wide/modelled labels) and the caveat that these are typical published take-home fees, not a quote, which is genuinely useful context beyond the annotations.

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?

Front-loaded with what the tool returns before the usage examples, and nearly every clause carries information (source, statistic, caveats, exclusions). It is a single dense paragraph, which reads as slightly run-on, but there is little waste.

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 explaining the shape and meaning of results (median, range, sample size, data-quality labels). With annotations covering safety and the schema covering parameters, an agent has everything needed to call this 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 including defaults, fallback behaviour and enum meanings. The description mainly reinforces existing constraints (pass a city not a region, omit for UK-wide, several cities to compare) rather than adding new syntax, so it sits at the high-coverage baseline.

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/resource with the exact statistic returned (median and 25th-90th percentile fees by city, gig type and act size) and names the data source (GigXchange Index). It is clearly distinguishable from siblings like get_index_summary or list_cities, which supply the city/issue inventory rather than fee figures.

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?

Gives concrete triggering questions ("what should my band charge", "what does a wedding band cost in Leeds") and an explicit comparison workflow ("pass several cities to compare"). It also states exclusions directly: regions are not accepted, pass a city; there is no genre dimension.

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