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

Beyond the readOnly/idempotent/non-destructive annotations, the description reveals key behaviors: internal cascading through multiple lookup endpoints, graceful degradation when GLEIF/OpenFIGI is unavailable, returning figi_candidates instead of asserting an ambiguous match, labeling identifiers by source, and listing unresolved IDs explicitly under `unresolved`. No contradiction with annotations.

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 organized by supported type and front-loaded with example queries and the primary use instruction. Most sentences carry necessary operational detail; the length is justified by the tool's complexity, though some parenthetical depth could be trimmed without losing essential 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 two-parameter tool with no output schema, the description is exceptionally complete. It covers input variants, per-type return contents, ambiguity handling, failure degradation, and unresolved-ID behavior. An agent has enough understanding to select and invoke the tool correctly and to interpret likely outcomes.

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?

Though schema coverage is 100%, the description adds substantial semantic value far beyond the schema. It explains accepted inputs for company (ticker, CIK, ISIN, name), gives a critical formatting warning for bond issuers, clarifies ISIN-to-LEI behavior, and provides drug examples. This meaningfully improves the agent's ability to pass the correct `value`.

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') with a clear target: user-spoken names to canonical/official identifiers needed by other tools. It provides concrete example queries, distinguishes two supported types (company, drug), and implicitly separates itself from siblings like entity_profile by focusing on ID resolution rather than profile lookup.

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 explicitly states 'Use FIRST whenever you have a name but need an ID,' giving strong situational guidance. It also details when to use company vs drug and warns about bond issuer-name formatting. It stops short of full 5 because it never explicitly states when NOT to use this tool or names alternative sibling tools for comparison.

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