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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds genuinely new behavioral context the annotations cannot express: a free daily allowance followed by $0.002 USDC per call via x402, which tells the agent to expect a paid/rate-limited surface and to budget calls.

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 sentences with zero waste: the purpose is front-loaded and the pricing constraint follows. Nothing needs trimming or reordering.

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 an output schema present, return values need no explanation, and the single parameter is fully documented. Pricing and read-only behavior are covered; the only real gap is the missing comparison to overlapping GLEIF search tools.

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?

There is a single parameter ('q', described in-schema as 'Partial name') with 100% schema description coverage, so the baseline is 3. The description adds no syntax, length, or matching-rule detail beyond what the schema already provides.

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 states a specific verb and resource: 'Name autocompletion across the LEI index.' An agent can tell this is a typeahead/prefix suggestion tool rather than a general lookup. However, it never names the nearby siblings it overlaps with (gleif__search, gleif__fuzzy), so the boundary is left to inference.

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: nothing says to reach for this while a user is typing a partial name versus calling gleif__search or gleif__fuzzy for a complete query. The only condition stated is economic (free allowance, then per-call price), not functional, so the agent gets no routing help.

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