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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the write/no-op profile is covered. The description adds value beyond that: the note is visible to everyone with website access, it consumes no keyword quota, and omitting keyword_ids silently broadens scope to the whole website. Return payload is not described, but the safety and side-effect picture is good.

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 WRITE marker and the core purpose, then appends the scoping rule, the visibility/quota caveats, and the endpoint — every clause carries information. The single long, semicolon-chained sentence is dense but not padded.

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 no output schema, an agent might still want to know whether the created annotation's id is returned, but the description covers the operation's scope, permissions implications, and cost, which is what matters for correct invocation. Adequate for a 4-parameter create tool.

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 100%, so 3 is the baseline. The description goes past the schema by explaining the consequence of omitting keyword_ids (global note) and by framing description/date as the note text and display date, adding semantic weight rather than restating field docs.

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?

Opens with an explicit verb ('WRITE: add'), names the resource (a user annotation), and describes what it is concretely ('a note shown on the ranking graphs, e.g. Launched new landing page'). The scope (date, optional keyword linkage, global otherwise) makes it trivially distinguishable from the read-side sibling wincher_list_annotations.

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 clear selection context: supply keyword_ids to tie the note to keywords, omit them for a global website note, and states it consumes no keyword quota (a real usage consideration for a quota-limited tool). It does not explicitly name alternatives or state when not to use it, 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.