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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is fully covered. The description usefully adds that results are ranked and include FRN/IRN plus a status summary, which matters since there is no output schema, but it says nothing about pagination, result caps, or rate limits.

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?

Two tight sentences, front-loaded with purpose then a concrete invocation. The example is slightly redundant with the schema's own examples array, but nothing 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 read-only search tool with full schema coverage and annotations covering safety, the main remaining burden is describing returns, which it does (ranked matches, FRN/IRN, status summary). Only the lack of sibling routing guidance leaves a gap.

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 each parameter is documented in the schema, so the baseline is 3. The inline example shows q and type in use, but adds no meaning beyond the schema's own example and enum description.

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 (Search) and resource (FCA Financial Services Register) and even sketches the return (ranked matches with FRN/IRN and a status summary). It does not explicitly differentiate itself from close siblings like fca_individual_lookup or fca_firm_details, though the name and the type param imply the distinction.

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?

There is no when-to-use guidance and no mention of alternatives such as fca_firm_details or fca_individual_lookup, even though the description itself notes it handles individuals and funds. The agent must infer the routing decision from the tool name alone.

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