Update service

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

Annotations already declare the safety profile (idempotent, non-destructive, open-world), so the description is not the sole bearer of that. Still, it adds no behavioral context: nothing about whether omitted fields are preserved or reset, what permissions are required, or how conflicts between ports/tags are handled. For a mutation tool, the description contributes essentially nothing beyond the title.

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 with zero filler, which is efficiently sized for what it says. It is under-specified rather than verbose, but there is no wasted text to penalize structurally.

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 4-parameter mutation tool with no output schema, the description omits the most important semantic detail: whether this replaces the configuration or merges into it. Annotations cover safety, but the merge/replace ambiguity and the required-serviceName precondition leave an agent guessing.

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 all four parameters (serviceName, tags, ports, autoApproveHosts) are already documented in the schema with types, bounds, and enum for protocol. The description adds no meaning beyond that, so the baseline of 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?

States a specific verb (update) and resource (Tailscale Service's configuration), which is clearer than the bare name alone. However, it offers no differentiation from siblings such as tailscale_get_service or tailscale_delete_service, nor from other update_* tools, so an agent gets no routing signal beyond the noun.

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 gives no when-to-use guidance, no prerequisites (e.g., the service must already exist), and no named alternatives. It never says whether this is a partial or full-replace update, which is the central usage question for an update call.

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