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

Beyond the annotations (which only say it is a non-destructive write), the description discloses two non-obvious traits: a hard capacity of 25 slots per website and that the platform auto-generates the title and description. It omits what happens on slot exhaustion and what the call returns, which matters since idempotentHint=false.

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 tightly packed sentences with the core behavior first and the routing guidance second; nothing is padding. The garbled 'Cactal titles and describes it' phrase costs a little readability but the intent (auto-titling) is recoverable.

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?

With only two parameters and no output schema, the description covers the essential mental model: persistent, searchable, agent-readable, capped at 25, auto-titled. What an agent still cannot predict is the return payload (entry id?) and failure mode when the slot budget is exhausted.

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 50% — text is documented (plain text or Markdown, 1,000,000 char cap) while websiteId has no description anywhere. The description's 'pasted or typed text' reinforces the text parameter but never explains that websiteId identifies the target site or how to obtain it, so the gap is not compensated.

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 action and resource — it persists pasted/typed text as a context entry that the agent later searches and reads — and explicitly distinguishes that content from the sibling 'agent notes' channel. An agent can tell this apart from websiteKnowledge_update or websiteKnowledge_agentNotes_edit without opening a schema.

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?

"Use this for material the user gives you to keep; your own findings belong in agent notes" gives a clear positive trigger plus one named exclusion. It does not say when to update an existing entry instead of creating a new one, nor what to do once the 25 slots are full.

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