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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so the description focuses on what annotations cannot convey: the substring+prefix ranking over slug/branded_name/name/category, the result set fields, and a worked example of how a query maps to ranked hits. Remaining gaps are edge behavior — zero-match handling, case sensitivity, and ordering ties — none of which are stated.

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?

Front-loads purpose, then returns, then mechanics, then the routing hint — a sensible order with no filler. The 'e.g. savings' example is informative but occupies a sizable share of the text, making the whole slightly longer than strictly necessary.

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 no output schema, the description carries the burden of describing return values and does so (ranked matches with slug, branded name, underlying name, category, canonical URL). Combined with the scoring explanation and the pointer to get_indicator, an agent has everything needed to call this correctly and use the result.

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 both parameters are already fully documented, including the default 10, cap 50, and clamping. The description restates the default and max limit and the query matching fields, adding no syntax or format detail beyond the schema, so the baseline of 3 applies.

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 and resource ('Search the 121-indicator registry by keyword') and immediately describes what it returns (slug, branded name, underlying name, category, canonical URL). It is clearly distinguishable from get_indicator, which the description names as the follow-up step once a slug is discovered.

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 says when to use it: 'when you want to discover which slug corresponds to a concept before calling get_indicator' — a clear discover-then-fetch workflow. It lacks any when-not guidance and does not distinguish between the get_indicator and get_indicator_v2 siblings, leaving slight ambiguity about which fetch tool to chain into.

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