references_add

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

No annotations are provided, so the description carries the full burden. It does disclose a real behavioral trait beyond the schema — persistence into the library and influence on future suggestions — but omits what happens on duplicate entries, whether the operation overwrites, and what the call returns (no output schema exists to cover that).

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, front-loaded with the action and effect, then the one hard constraint. No filler; every clause carries information an agent needs.

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 7-parameter mutation tool with no annotations and no output schema, the description covers the primary flow but leaves gaps: nothing about the return value, duplicate handling, or the meaning of the required 'medium' enum. Adequate to attempt a call, not complete enough to call it confidently with all parameters.

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?

With only 43% schema coverage the description must compensate, and it partially does: it maps 'a link, a screenshot path, or both' to url/image and stresses that 'take' is always required. However, it says nothing about 'medium' (a required 10-value enum with no schema description), 'title', 'tags', or 'topic', leaving several parameters explained only by their bare names.

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+resource ('Save a reference ... into their library') and adds an effect ('so it is suggested from now on'), which is more than a restatement of the name. It doesn't explicitly differentiate itself from siblings like references_suggest or references_shortlist, but the write-versus-read distinction is inferable from 'Save'.

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?

'Save a reference the user handed you' gives a clear trigger condition for invocation, and the stated downstream effect clarifies why one would call it. There are no explicit exclusions or named alternatives, so it stops 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.