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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds substantial behavioral context: it cascades through multiple lookup endpoints, degrades gracefully if GLEIF/OpenFIGI are unavailable, explicitly lists unresolved identifiers under `unresolved`, and returns `figi_candidates` rather than asserting when ambiguous. It also clarifies that non-equity instruments resolve even without tickers. 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?

Although long, the description is tightly organized: it starts with usage examples, then the core purpose, then detailed per-type behavior, and finally notes about degradation and efficiency. Every sentence carries necessary information for correct invocation, and the structure front-loads the most critical guidance. The length is justified by the tool's complexity.

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 fully explains return behavior: identifiers, source labeling, `unresolved` field, `figi_candidates` for ambiguity, and graceful degradation. It covers edge cases (non-US issuers, bonds, ambiguous names) and input constraints. An agent can correctly call this tool without additional documentation.

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 provides only basic descriptions for `type` and `value`. The description enriches both: for `value`, it lists accepted formats (ticker, CIK, ISIN, name) for company, and brand/generic for drug, with a concrete example and a warning against including trailing security-class words. It also explains the behavior for ambiguous names, adding meaning far beyond the schema fields.

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 opens with concrete user-phrase examples and then states the core purpose: 'resolve a user-spoken NAME to the canonical/official identifiers other tools require as input.' It specifies the verb 'resolve,' the resource (entities with types), and explicitly differentiates from siblings by saying 'Use FIRST whenever you have a name but need an ID.' This leaves no ambiguity about what the tool does.

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?

The description gives explicit when-to-use guidance: 'Use FIRST whenever you have a name but need an ID.' It also details when to use each type (company vs drug) and provides input format rules, including a critical caution about bond issuer names. It notes the tool replaces 2-3 manual lookups and explains how ambiguous matches are handled, so an agent knows exactly when to call it versus alternatives.

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