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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds valuable behavioral context beyond annotations: it 'Reads the working copy; no LLM call', which informs cost and latency, and it details what the response identifies (shared definition usage, identity participation, etc.). It also warns that 'Editing a $defs property affects every usage site', a useful consequence for the editing workflow. This goes beyond the annotations and enhances transparency.

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 dense but well-structured: it opens with the core purpose, then explains path syntax, response content, an editing caveat, and finally a note on working copy/no LLM. Each sentence adds value; there is minimal redundancy. While it is longer than minimal, it is organized front-loaded and earns its length through necessary usage details.

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 presence of an output schema (which defines the return format) and annotations covering read-only/destructive safety, the description completes the picture by explaining how to target different schema parts, what the response highlights, and the implication of editing shared definitions. It also clarifies the working copy and no-LLM behavior. Nothing an agent needs to call this tool correctly is missing.

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%, so both parameters are documented. The description adds meaning beyond the schema by detailing path variants ('$defs.X', '$enums.X', object/leaf paths) and giving the array syntax '[]'. It also provides a concrete example (enricher://docs/schema-reference), which helps an agent construct valid paths. This exceeds the baseline for high schema coverage.

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 specific verb and resource: 'Read only the schema fragment needed for an edit.' This clearly states the tool's function and its scoped purpose, distinguishing it from siblings like get_schema (which likely returns the full schema). The detailed path semantics further clarify exactly what can be fetched, leaving no ambiguity about the tool's role.

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 strong contextual guidance: it's for reading a fragment 'needed for an edit', and it gives explicit path syntax (e.g., '$defs.X', '[]' for arrays). However, it does not explicitly name alternatives or state when NOT to use this tool (e.g., 'for the full schema, use get_schema instead'). The context implies the right usage but lacks an explicit exclusion or comparison.

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