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

Annotations already mark the tool read-only and idempotent, and the description adds a meaningful behavioral caveat: a DID in a query is not accepted as proof, so a valid controller signature and nonce are required. This goes beyond the structured hints and clarifies an important precondition.

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 only two short sentences and every clause earns its place: endpoint identification, result scope, and the critical DID-proof warning. It is front-loaded and contains no filler.

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 rich 100% schema, output schema, and read-only/idempotent annotations, the description only needs to supply selection context and critical proof requirements, which it does. The main gap is that 'what you own' remains somewhat dependent on domain knowledge about Neon/city.json, but the structured fields carry the rest.

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 description coverage is 100%, so the parameter semantics are fully documented in the schema. The top-level description adds only the general proof requirement rather than new per-parameter detail, which matches the baseline for complete schema coverage.

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 names the endpoint (GET /api/own) and states the tool returns 'What you own' from the same Neon sources as city.json, so the core purpose is clear. The 'Proven' prefix and the DID warning add that ownership must be proven, but it does not explicitly differentiate from sibling tools.

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?

The intended use is implied by 'What you own' — call this when you need the caller's owned resources with proof. There is no explicit when-to-use vs alternatives or exclusion guidance, so the agent must infer the use case.

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