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

With no annotations, the description carries the burden and handles it well: it discloses the census/cached nature, the periodic rebuild, the coverage field, and the risk of mistaking a partial answer for final, plus free/no-signup access. This goes beyond a simple read hint.

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?

Three compact chunks—purpose, provenance/coverage caveat, and param/access note—are front-loaded with no filler. Every sentence adds decision-relevant information.

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 one-parameter read tool with no output schema and no annotations, the description covers what data is returned, that it may be partial, and what access is needed. It does not spell out the exact response shape or update cadence, but these are minor for invocation.

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 fully documents issuer_address with a description, so the description adds little beyond restating it as required and noting the r-prefix. Baseline 3 is appropriate when schema coverage is complete.

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 uses a specific verb ('Get'), names the resource ('everything an issuer account has issued'), and enumerates the returned dimensions (credential type, distinct subject count, acceptance rate), making it clear what the tool does and separating it from account-level or MPT-focused siblings.

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 issuer-account wording and the list of aggregate metrics provide a clear context for when to call it. It does not explicitly name alternatives or say when not to use it, so it stops 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.