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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds genuinely useful context by disclosing a cost of 1 credit, but says nothing about coverage limits (e.g. non-UK points yielding no result) or how missing neighbourhood data is represented.

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?

A single compact sentence with the resource front-loaded and the credit cost in parentheses, no filler. It is slightly fragmentary because it omits an explicit verb, but nothing in it is wasted.

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 two-parameter, annotation-rich lookup with no output schema, the description carries the key extras: what is returned (force, team, contacts) and the credit cost. Geographic coverage would be a nice addition but nothing essential for correct invocation 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 coverage is 100%, so latitude and longitude are documented in the schema itself, and 'for a point' merely confirms both are needed. The description adds no format, range, or coordinate-system detail beyond what the schema already provides, so the baseline of 3 applies.

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?

Names the concrete resources returned — police force, neighbourhood team and contact details — and scopes them 'for a point', which distinguishes it from siblings like mp_lookup or govuk_search. No explicit verb (lookup/retrieve) is given, but the resource is unambiguous.

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?

Usage is only implied: the phrase 'for a point' tells the agent this is a coordinate-based lookup, but there is no statement of when to prefer it over alternatives or what preconditions apply. An agent can infer the use case but gets no routing guidance.

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