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

Annotations are sparse (readOnlyHint=false, destructiveHint=false), so the description carries weight. It adds useful context: 'Not metered' and 'requires a free Prowlo account.' However, it does not disclose what happens when the tool is invoked (e.g., mutation, no-op, or error), and the phrase 'call it to get a signup link' is ambiguous about whether 'it' refers to this tool.

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?

The description is short and front-loaded with the deprecation warning. The alternative is named efficiently. The parenthetical about the signup link is somewhat confusing and could be clearer, but overall it is concise.

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 deprecated tool, it clearly signals to avoid using it and points to the replacement. However, it does not explain the actual effect of calling watcher_add_source, and with no output schema, return behavior is unspecified. This is adequate but lacks full operational detail.

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 each parameter already has a meaningful description. The tool description adds no parameter-specific meaning beyond the schema, so the baseline 3 is appropriate.

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 leads with 'Deprecated' and explains that a Watcher watches exactly one community/query, but it never explicitly states that the tool adds a source to a watcher. The alternative name watcher_create helps distinguish it, but the core purpose is only inferable from the tool name and 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?

The description explicitly instructs the agent to 'Use watcher_create to watch another community' and explains why (one Watcher per source). This is a clear when-not-to-use directive with a named alternative, which is exactly what a deprecated tool needs.

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