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

With no annotations, the description carries the full behavioral burden. It adds real value by disclosing that active=false pauses scanning and that email can be instant or held for a roll-up, but it omits whether this is a partial update, whether omitted fields are preserved, permission requirements, and whether pausing affects queued scans.

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?

A single front-loaded sentence that names the resource first and then enumerates the capabilities in a compact colon list. Every clause maps to an actual parameter; nothing is padding.

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 6-parameter, all-optional mutation tool with no annotations and no output schema, the description covers every mutable field and the pause/resume effect. The one meaningful gap is that it never states that at least one field should be supplied, since nothing is marked required.

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 the schema already defines each field, and the description largely restates those fields in prose. It adds no syntax, format, or interaction detail beyond what the schema provides; baseline 3 applies.

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 gives a specific verb (update) and resource (watch) plus an enumeration of the mutable attributes — rename, cadence, email, notes, pause/resume — so the agent knows exactly what surface it touches. It does not explicitly contrast itself with siblings like delete_watch or add_watch, keeping it below a 5.

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?

Usage is implied: modify an existing watch rather than create or delete one. There is no explicit 'use X instead when…' routing and no statement of prerequisites, though the schema's watchId hint ('from list_watches') partly compensates.

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