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

Annotations already declare readOnly, openWorld, idempotent and non-destructive, so the safety profile is covered; the description adds real value on top: live public-index sourcing, XLSX/CSV output files, five candidates max per name, and that ambiguous matches require user choice. It doesn't mention rate limits or auth, but nothing critical is missing for a read-only lookup.

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 the trigger condition, then the input limits, then the exclusion — all in three compact sentences with no filler or repetition.

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?

Given an output schema exists and annotations cover safety, the description supplies the remaining operational details (input caps, candidate count, ambiguity handling, output format). Only the sibling-alternative mapping is left implicit, which keeps it just under complete.

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 coverage is 100% and both the name-length (2–200) and 25-name limits are already stated in the schema descriptions, so the description largely restates structured data. The five-candidates-per-name note adds slight context but is a result property rather than a parameter semantic.

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+resource: finding LEIs by company name, with an explicit synonym set (lei search, legal entity identifier lookup). It distinguishes itself from verify_leis only indirectly via the 'not for ownership verification' line rather than by naming siblings, so it falls short of full differentiation.

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?

Gives a clear trigger condition ('when the user wants to find lei by company name...') and an explicit exclusion ('Do not use for ownership verification'), which routes agents away from get_lei_parents/verify_leis. It never names the alternative tools, so agents must infer which sibling to use instead.

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