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

Annotations are neutral (all false), so the description carries the burden of disclosing behavior. It adds a size limit and a caution about large outputs, which is useful, but it does not disclose other behaviors like persistence, overwrite semantics, or return values. It adds some value beyond annotations, but leaves gaps.

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 sentences with no fluff: the first states the purpose and limit, the second provides a critical warning. Information is front-loaded and every word 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 3-parameter tool with no output schema, the description should at least clarify the role of each parameter and whether anything is returned. It covers the content and size, but leaves kind and label unexplained and says nothing about the result of the store operation. Given the neutral annotations, more context is needed for confident invocation.

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 description coverage is 0%, so the description must compensate for parameter explanations. It mentions 'content' and the 16 KiB size limit, but does not explain the 'kind' (text/json/csv) or 'label' parameters. The enums and defaults are in the schema, but the agent gets no guidance on how to choose them, leaving important semantics unclear.

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?

The description states a specific verb ('Store') and resource ('small note, text or JSON string') with an explicit size limit, making the core function clear. It does not explicitly contrast with sibling tools, but the name and the mention of 'small' help distinguish it from other mithrandir operations.

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?

The description implies usage by warning not to paste large tool outputs here and directing them to the host SDK, but it does not explicitly name an alternative mithrandir tool or state when to prefer this over siblings. Guidance is present but only implied.

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