plan_fixture

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

With no annotations provided, the description carries the full burden. It explicitly discloses key behaviors: it is privacy-safe, creates a plan rather than actual data, and does not fabricate or copy example data. This goes beyond a generic 'create' tool, though it does not detail return values or side effects, so a 4 is appropriate.

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 two sentences with no waste. The first sentence front-loads the verb and resource, and the second sentence adds an important behavioral caveat. Every word earns 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?

For a simple tool with a single well-documented parameter, the description covers the purpose, a key constraint (local file), and a behavioral guarantee (privacy-safe, no copying). It does not explain the exact output format, but given the tool's name and description ('create a plan'), this is likely self-evident. Overall, reasonably complete.

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?

The input schema already covers 100% of the single parameter 'file', including a description ('Local JSON Schema file. Network URLs are not accepted.'). The tool description reinforces the 'local' aspect but adds no new meaning beyond the schema, so the baseline score of 3 is correct.

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 ('Create') and clearly identifies the resource ('privacy-safe placeholder plan for test fixture fields in a local JSON Schema'). It also states what the tool does not do ('does not fabricate or copy example data'), which distinguishes it from sibling inspect_schema that likely focuses on reading schema details.

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 gives clear context about what the tool does and its privacy-safe nature, implying when to use it (e.g., when needing test fixture placeholders without copying data). However, it does not explicitly mention when not to use it or name alternatives such as inspect_schema, so it falls short of a full 5.

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