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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds meaningful non-schema context: the result carries a last-verified date and a data-confidence indicator, warning the agent the data may be stale or partial.

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 the returned data, then the identifier rule, then the exclusion. Three sentences, no filler. The returned-field list is dense but each item is informative rather than padding.

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?

There is no output schema, so the description usefully enumerates what comes back (fee, period, notice, renewal, link, freshness, confidence) and how to identify the council. Coverage is good; it does not mention behaviour when a council has no permit scheme or no data, which would round it out.

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 coverage is 100% and both parameters are documented there, so the baseline is 3. The description adds a genuine constraint absent from the schema (which lists no required fields and no oneOf): exactly one of council_name or town_slug must be supplied, which materially changes how the agent calls it.

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 resource (council skip permit rules) and enumerates the exact fields returned (fee, permit period, notice needed, renewal, application link, freshness). This clearly separates it from get_skip_prices and recommend_skip_size without needing to open any schema.

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 a concrete exclusion ('A skip on a private driveway needs no permit') and an input constraint ('Provide exactly one of council_name or town_slug'), which steers correct invocation. It does not explicitly name a sibling as the alternative for price or sizing questions, so it stops short of full when/when-not routing.

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