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

Adds substantial context beyond annotations: returns {id, length} for self-verification, expectedRev acts as optimistic concurrency (REJECTED with nothing written if the body moved), short-form 8-char prefix accepted, and artifact behavior with automatic public-link refresh. This discloses write semantics and failure modes the annotations alone don't.

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?

Front-loads the core action, then layers value (cheaper, use cases, separator, return shape, concurrency, artifacts) with no filler. Dense but every sentence carries actionable 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?

No output schema exists, yet the description states the return value ({id, length}) and describes the concurrency guarantee and artifact side effect. For a 4-param append tool this is complete enough for an agent to call correctly.

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%, so baseline is 3, but the description adds usage guidance the schema lacks—specifically when to omit expectedRev ('read-then-immediately-write, or when appending blind') and the separator default behavior. This meaningfully augments the expectedRev parameter's semantics.

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 ('append') and resource ('a memory's body') with scope ('to the END'), and implicitly distinguishes from full-body update by noting it's 'cheaper than resending the whole body.' An agent can tell exactly what this does versus sibling memory tools.

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 concrete use cases ('growing changelogs, journals, session-state, or any memory that accumulates by accretion') and contrasts cost with resending the whole body, which implies the alternative update path. It doesn't explicitly name muninn_memory_update as the alternative, keeping it just short of a 5.

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