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

Annotations already flag destructive=true, idempotent=false, openWorld=true, but the description adds substantive behavior beyond them: fields are replaced with no restore history, sharing with the team is a possible side effect, explicit approval is required, and stale revisions fail. These are exactly the traits an agent needs before making a mutating call.

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?

Four tight clauses with zero filler, front-loaded with the core action followed by mutation semantics, side effects, and constraints. Each sentence carries distinct information an agent needs.

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?

Given the deeply nested schema and an existing output schema (so return values need no explanation), the description covers purpose, mutation/replacement semantics, concurrency handling, approval requirements, sharing side effects, and an explicit non-goal. Nothing essential for a correct call is missing.

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 67%, so moderate compensation is expected. The description names the nested path update.expectedRevision and explains its failure semantics ("stale revisions fail"), which adds real meaning, but templateId and conversationFiles receive no interpretive help beyond the schema itself.

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 states a precise verb and resource ("Updates one owned Custom template") and scopes it to owned Custom templates specifically, which separates it from list/save/use/delete template siblings. The closing clause "Does not start research" explicitly walls it off from the study-run tools (start_study_run, ask_study).

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?

It gives clear context for use: the template must be owned, it operates at a specific expected revision, and it explicitly excludes starting research. However, no alternative tool is named, so the agent gets an exclusion but not a positive routing rule (e.g., save_study_template for new templates).

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