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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the description adds value by specifying the data source (HM Land Registry), licensing (OGL v3.0), and the no-auth requirement, which are beyond the annotation basics. This gives the agent confidence about safe usage and data provenance.

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?

The description is concise (3 sentences) with key info upfront: what it does, the prerequisite, and data provenance. No waste, and every sentence serves a purpose.

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 a single parameter fully documented by the schema, an output schema handling return values, and annotations covering safety, the description provides all the extra context (prerequisite, data source, licensing) needed for correct invocation. Nothing 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?

The schema already documents the parameter with a description and example, and 100% schema description coverage means the description adds no extra parameter meaning. Baseline 3 is appropriate; the tool name also provides clarity.

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?

The description clearly states the tool gets a single transaction by GUID and lists the return fields. It is distinct from siblings by_area and by_postcode, which are search tools, making the purpose 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?

Explicitly instructs to call search_by_postcode or search_by_area first to obtain the transaction_id, providing clear prerequisite context. Though it doesn't name exact siblings, the search tools are obvious from the instruction, and no exclusions are needed.

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