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

readOnlyHint=true already covers the safety profile, so the bar is lower; the description still adds real context beyond it — the fallback chain (custom → default) that determines what actually comes back, the fact that the response identifies the project via profile_id, and an explicit access prerequisite (Proof account, client authentication, and the note that start_login does NOT unlock this tool). It stops short of noting rate limits or the full response shape.

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 core capability and its fallback rule are front-loaded in one dense sentence, followed by the return-value note and the access caveat. The ACCESS block is somewhat boilerplate, but it is short and operationally necessary given the authentication prerequisite.

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 read-only lookup with no output schema, the description supplies what an agent needs: what gets resolved, what the response identifies, and the auth precondition that must be satisfied first. Only the precise response payload beyond profile_id is left unspecified, which is acceptable with no output schema.

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 channel, profile_id, and message_type are already documented in-schema; baseline 3 applies. The description adds only marginal meaning by restating the channel/message_type pairing and clarifying that profile_id identifies the project in the response — useful framing but not new per-parameter syntax or constraints.

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+resource (get the template) and goes further by defining the resolution rule: custom template at scope "project" if set, otherwise the channel/message-type default at scope "default". This meaningfully separates it from get_default_templates and list_templates, though those siblings are never named explicitly.

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 establishes the retrieval context (per sub-account, per channel, per message type) but never says when to prefer this over list_templates, get_default_templates, preview_template, or render_template. Usage is inferable from the resolution semantics rather than stated, and no exclusions or alternatives are given.

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