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

readOnlyHint already declares the safe-read profile, but the description adds genuinely useful behavior beyond annotations: unavailable IDs surface in the `notFound` field rather than erroring, and rule lookups use slugs while records use UUIDs. That is real operational context not available in structured fields.

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 tight sentences, front-loaded with what is returned and how it is keyed, followed by when it is useful. No filler; the notFound detail 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 single-parameter read tool with no output schema, the description covers input formats, scoping, and the partial-failure behavior (notFound). Return shape beyond that is unspecified, but nothing essential to correct invocation 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% and the single `IDs` parameter is already documented, so baseline is 3. The description adds meaning above the schema by explaining the two ID formats (rule slugs vs. memory-record UUIDs) and the example `git`, clarifying what values are actually valid.

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 (Returns) and resource (agent memory records and MCP rules) with the key differentiator: full retrieval by ID, contrasted with the `memory` index used for discovery. An agent can distinguish this from memory_list 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?

Gives clear context ('Useful when a record from the `memory` index is relevant to the user's task'), which implicitly positions this as the follow-up to index/search tools. It does not explicitly name an alternative or state when not to use it, so it falls just short of 5.

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