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

Annotations cover the safety profile (read-only, non-destructive, closed-world), and the description adds substantial behaviour beyond that: the entitlement requirement, the null-not-zero convention for missing figures, a per-call cost of 25 tokens, and the crucial caveat that the footfall figure is a comparative index, not a head count. That last point prevents a serious misinterpretation an agent would otherwise make.

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 it returns, then constraints and caveats. The long metric enumeration is dense but each item carries information; the definition is not padded, though the opening sentence is heavy for a single sentence.

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?

With no output schema, the description takes on the burden of describing what comes back and does so thoroughly — footfall splits, resident age bands, income bands, and amenity categories — plus cost, entitlement, and null handling. An agent has everything needed to call it and interpret the result 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 coverage is 100% and the schema already explains id vs lat/lon and the lang enum in detail. The description only restates the id-or-point choice without adding format or constraint detail, so it sits at the baseline for a fully documented 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?

States a specific verb+resource: location intelligence metrics (footfall index, resident demographics, nearby amenities) for a premises id or a lat/lon point in Spain. The enumerated metric families make it clearly distinct from siblings like claro_get_premises or claro_compare_premises.

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?

Makes the input choice explicit (a premises id, or a point via lat/lon) and states a hard prerequisite: the organisation's plan must include Location Intelligence. It does not explicitly name sibling alternatives or when to prefer claro_compare_premises for multi-site comparison, which keeps it short of a 5.

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