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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: it is a premium API with a specific cost ($0.25 USDC via x402), which is important for an agent deciding whether to invoke it. It also discloses the breadth of the response (issuer type, credit standing, debt, pension exposure, etc.). 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 a single, information-dense sentence that front-loads the core purpose and then lists the profile contents. The cost disclosure is a necessary addition. It is slightly long but every clause earns its place; no filler.

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 read-only lookup tool with one well-documented parameter and no output schema, the description covers the input, the output scope, and the cost. It does not describe the exact response format, but with no output schema and a research-profile tool, the listed content areas are sufficient for an agent to know what to expect. The cost disclosure is a notable completeness plus.

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 the single parameter 'lookup' has a clear description and example. The tool description adds context about what the lookup value should be (a municipal issuer name) but does not add much beyond the schema. Baseline 3 is appropriate.

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 states a specific verb ('Retrieve') and resource ('research profile on any US municipal securities issuer'), enumerates the issuer types and the profile contents, and distinguishes it from sibling tools by its domain (municipal securities). It is immediately clear what this tool does and how it differs from the many other interzoid_* tools.

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 implies when to use it: whenever an agent needs a research profile on a US municipal securities issuer, and it lists the covered issuer types. It does not explicitly name alternatives or exclusions, but the domain is narrow enough that the usage context is clear. A small deduction for not explicitly saying 'use this instead of X'.

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