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

Even with readOnly/openWorld/idempotent annotations, the description adds crucial behavior: graceful degradation when GLEIF/OpenFIGI is unavailable, explicit `unresolved` output, ambiguous matches returning `figi_candidates` without asserting, identifiers labelled by source, and internal cascade. This gives the agent a reliable model of side effects and edge cases.

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 long and dense, but it is front-loaded with purpose and usage, then organized by supported type. Each paragraph earns its place; the length is justified by the tool's edge cases, though tighter sentence grouping would improve scannability.

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 explaining return behavior, and it does: resolved fields per type, unresolved handling, ownership data, citation, ambiguity, and degradation. An agent has enough information to invoke correctly and interpret results.

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 covers syntax, but the description adds high-value guidance: accepted input forms (ticker/CIK/ISIN/name; brand/generic), ISIN-to-LEI behavior, and a precise warning to pass the bare entity name, not the full noun phrase, for bonds. This materially prevents misinvocations.

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 ('resolve') and resource ('a user-spoken NAME to canonical/official identifiers other tools require as input'), with example queries and two entity types. It frames itself as the first step for name-to-ID lookups, setting it apart from sibling tools that operate on IDs or knowledge.

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?

It gives a clear trigger: 'Use FIRST whenever you have a name but need an ID,' plus query patterns and a note that it replaces 2-3 manual lookups. It doesn't explicitly name sibling tools or state when not to use it, so it falls just short of full exclusions/alternatives guidance.

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