Fetch a Metro author profile by author slug or page URL. Results include name, job title, bio, image, topic areas, social profiles, and up to about 30 recent articles; use this for one correspondent.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes | The tool result payload (shape varies per tool; see each tool's docs resource). |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful content-shaping detail (about 30 recent articles included), but says nothing about fetch failures, missing-slug behavior, or rate limits. Adequate given the annotation coverage, not rich.
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, front-loaded with purpose and identifier types. The enumerated field list is slightly verbose and overlaps with the existing output schema, but nothing is wasted enough to obscure the core instruction.
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?
An output schema exists, so the description need not explain return values, and the input ambiguity (slug vs URL) is resolved. Missing behavior for invalid or unknown authors is the only notable gap for a single-parameter read tool.
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 0% and the single parameter is an undescribed "url" string. The description compensates by revealing that either an author slug or a page URL is accepted, which the schema does not convey. It stops short of giving an example format, so it is a strong but not complete compensation.
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?
Starts with a specific verb and resource ("Fetch a Metro author profile") and states the accepted identifiers (author slug or page URL). The trailing clause "use this for one correspondent" scopes it to a single author, distinguishing it from the site's article/headlines/sections tools without ambiguity.
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?
"Use this for one correspondent" implies the single-author use case, but no alternative is named and no when-not condition is given. An agent must infer that bulk or search-style author lookup is handled elsewhere; guidance is implied rather than explicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
