replace_mcp_config

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

With no annotations, the description carries full burden. It discloses a validation condition ('Rejected unless content parses as an object of objects') and a safety behavior ('the previous file is backed up either way'), which cover key behavioral traits. However, it doesn't mention any potential side effects beyond overwriting (e.g., losing entries not in the new content) or what happens on success, though the output schema likely covers return values. Slightly under-discloses for a destructive operation, but the backup note mitigates.

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?

Four short, purposeful sentences. The core action is front-loaded, followed by usage context, validation/backup behavior, and alternative routing. No filler or redundancy – every sentence 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 one-parameter tool with an output schema, this description covers purpose, usage context, validation, backup behavior, and alternative selection. Nothing essential is missing; the output schema handles return values, so the description's omission of success details is acceptable.

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 has 100% coverage for the single parameter, but the description adds meaningful extra semantics: 'complete JSON document' and 'object of objects', which clarify the expected structure beyond the schema's generic 'full replacement JSON text'. This helps the agent construct valid input without extra inference.

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 and resource ('Overwrite config/mcp.json') and clarifies it takes a complete JSON document. Differentiates from siblings by noting it's for 'restructuring several entries at once' and explicitly naming 'upsert_mcp_server' as the alternative for single-server changes, so the agent can distinguish tools without opening schemas.

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?

Explicitly states when to use this tool ('For restructuring several entries at once') and when not to ('Prefer upsert_mcp_server for a single-server change'), naming the specific alternative. This gives clear routing guidance with no ambiguity.

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