get_user_profile

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

With no annotations, the description carries the full burden. It clearly states the operation is a read ('Read the account'), lists returned fields, and explains the relationship to SUBSTACK_PUBLICATION_URL. This gives the agent a transparent view of safety and outcome, though it could go further with pagination or error behavior.

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?

Two sentences, zero fluff. The first sentence states purpose and payload, the second gives the distinguishing use case. Perfectly concise and front-loaded.

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 simple tool with one optional parameter and no output schema, the description covers purpose, return contents, and a specific use case (publication discovery). Nothing critical is missing; it is complete for this complexity level.

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% with a clear description of the 'full' parameter. The tool description does not explain the parameter, but the schema does. Baseline 3 is appropriate since the schema does the heavy lifting and the description adds no extra parameter context.

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 a clear verb and resource: 'Read the account behind the session'. It specifies the exact data returned (id, handle, name, bio, and publications) and distinguishes this tool's purpose from any sibling by noting it reveals all reachable publications, not just the one from SUBSTACK_PUBLICATION_URL.

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?

Provides a concrete use case: discover which publications the session can reach beyond the single publication URL. This implies when to use the tool, though it does not explicitly mention alternatives or exclusions. The guidance is sufficient for context.

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