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

Annotations only say it is a non-readonly, non-destructive, non-idempotent write. The description adds material behavior beyond that: the refusal of large replacements, the two-step save model (nothing persisted before studio_save), and the validity constraint on manifest.json.

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, each carrying a distinct constraint: write/append, the large-file refusal with its alternative, the manifest rule, and the save gating. No filler.

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 four-parameter write tool with no output schema, it covers the critical unknowns an agent needs: when writes actually persist, how to modify large files instead, and the structural rule for manifest.json.

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 50% and the undocumented parameters are append and content. The description compensates by explaining append=true's semantics and the whole-file vs. append distinction, though it says nothing extra about content or session_id.

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 (write) and resource (a whole file of the open page) plus an alternate mode (append=true). It also names the sibling it is not — studio_edit_file — so the tool is distinguishable without opening a 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?

Explicitly says a large existing file cannot be replaced and directs the agent to studio_edit_file instead, and warns that nothing is saved until studio_save. It also sets a constraint for manifest.json, so the when-to-use and when-not rules are concrete.

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