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

Annotations already declare read-only, non-destructive, closed-world semantics, so the safety profile is covered. The description adds real behavioral value beyond that: records come back 'in full' and 'unavailable IDs come in notFound', telling the agent how partial or missing input is handled.

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 with zero waste. The core action and ID semantics are front-loaded, and the usage hint plus notFound behavior follow without padding.

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 full schema coverage and annotations carrying the safety profile, the definition is essentially complete: it explains identifiers, completeness of results, and missing-ID handling. Without an output schema it could say a touch more about the return shape, but nothing needed for 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 schema description already states 'Rule slugs or memory record UUIDs'. The description largely repeats this, only adding the concrete slug example `git`, so it sits at the baseline for a fully documented schema.

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 its two resources (agent memory records and MCP rules), and clarifies the input shape ('in full by ID'). It is clearly distinguishable from sibling memory_list, which enumerates rather than resolves by ID.

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 an implied usage condition ('when a record from the `memory` index is relevant to the user's task') but no explicit when-not guidance and no named alternative (e.g. memory_list for browsing). Enough to orient the agent, but routing between memory_* siblings is left to inference.

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