echo

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

With no annotations, the description carries the full burden and does state the key behavioral fact: the input is returned unchanged, so the tool is side-effect free and deterministic. It doesn't discuss failure modes or payload limits, but for a trivial echo this covers the essential contract.

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 short sentences, zero filler, with the behavior stated first and the diagnostic purpose second. Nothing could be removed without losing information.

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, no-side-effect tool with no annotations and no output schema, the description supplies everything an agent needs: what it returns and why it exists.

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?

There is a single parameter with 100% schema description coverage ("the text to echo back"), so the schema already fully documents it. The description adds nothing beyond that — "the given text" merely restates it — so the 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 (echo) and resource (the given text) plus the exact transformation — returned unchanged — and adds that it exists to verify MCP wiring, which separates it completely from the memory_* siblings. An agent can identify the tool without opening the schema.

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?

"Used to verify the MCP wiring" gives a clear triggering context: call this to test connectivity/plumbing. It doesn't explicitly exclude other uses or name alternatives, but for a single-purpose diagnostic tool the guidance is unambiguous.

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