read_shapeReads one API shape and its fields by name, letting you inspect the schema a route accepts or returns.
Reads one shape of the API (a schema a route takes or answers with) and its fields.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | The shape, such as "Refusal", as read_endpoint names it |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint false and openWorldHint false, so the safety profile is fully covered structurally. The description adds only that fields are included in the result; it says nothing about failure behavior for unknown shape names or result size, which would have been the value-add.
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?
One front-loaded sentence with the verb and resource first, then the clarifying parenthetical. No filler, though the parenthetical is slightly dense compared to splitting the 'fields' detail out.
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 one-parameter read tool with rich annotations, the description is adequate but thin: it does not state how shape names are discovered (only the schema hints at read_endpoint), nor what the returned structure looks like beyond 'its fields'. No output schema exists, so a one-line return description carries that burden loosely.
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 description coverage is 100% and the single parameter already documents that 'name' is a shape such as "Refusal" as read_endpoint names it. The description adds no further naming, casing, or format guidance beyond the schema, so baseline 3 applies.
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?
States a specific verb (read) and resource (one API shape) and defines what a shape is ('a schema a route takes or answers with') plus what is returned ('its fields'). It does not explicitly distinguish itself from siblings like read_endpoint, though the concept is differentiated by the parenthetical.
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?
Usage is only implied: the reader infers this is the lookup to use once a shape name is known (e.g., from read_endpoint). There is no explicit when-to-use, no exclusions, and no statement of what to do if the shape name is unknown or ambiguous.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.