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

Annotations already declare the tool read-only and idempotent, but the description adds valuable behavioral context: outputs are deterministic and validated, the index layer is free, and all 4 content layers are gated behind a trial key on ethics. This goes beyond the annotation safety profile to explain access and output guarantees.

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 concise and front-loaded with purpose. Each sentence adds unique information: purpose, output determinism, free access, and gating. There is no fluff or repetition, making every word earn its place.

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 the tool's moderate complexity, rich schema (enum for verticals, descriptions for all params), and annotations, the description covers essential operational aspects: free vs gated layers, deterministic returns, and trial key requirements. It omits a detailed return format, but since no output schema exists, a high-level statement is acceptable and the description feels complete for its purpose.

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%—all three parameters have descriptions, so the baseline is 3. The description adds a bit of nuance (trial key for ethics content layers, free index layer) but does not elaborate on node or token formats beyond what the schema already provides.

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 'Retrieve' with the resource 'structured knowledge from Agent Module verticals,' clearly distinguishing it from sibling tools like get_trial_key or check_status. It also specifies output characteristics (deterministic, validated nodes), leaving no ambiguity about the tool's function.

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 provides clear context on when to use this tool: for knowledge retrieval, with the index layer always free and content layers requiring a trial key on ethics. It implies authentication requirements but does not explicitly contrast with alternatives or state when not to use, so it lacks exclusions.

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