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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false. The description adds a genuine blast-radius disclosure (affects every agent on the template) and partial-update semantics (only provided fields are updated), which is more than the annotations give. But it omits permissions requirements and whether changes take effect immediately, so it is a modest rather than rich addition.

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?

Three tight sentences, purpose front-loaded, followed by scope impact and update semantics. No filler or restated boilerplate.

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 non-destructive update tool with no output schema and fully documented params, the definition covers purpose, scope, override interaction, and partial-update behavior. It stops short of noting required permissions or the effect-on-response, which are minor gaps rather than blocking omissions.

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 coverage is 100%, so the baseline is 3. The description goes slightly beyond by grouping the fields conceptually and stating that all parameters except prompt_id are optional with only supplied fields applied, adding PATCH-like semantics not spelled out in the schema.

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 (prompt template) and enumerates the mutable fields (name, system instructions, auto-reply rules). It is clearly distinguishable from read siblings like prompts_get/prompts_prompt_history, but it never names those siblings explicitly to sharpen the contrast.

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?

Provides real context: changes affect every agent on the template unless the agent carries its own override set via agents.update → prompt_text. That gives the agent a routing signal toward the per-agent alternative. However, it does not state a positive when-to-use condition or explicit exclusion territory against the sibling prompt tools.

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