insert_at_placeholder

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

With no annotations, the description carries the full burden. It discloses that it replaces 'every occurrence' of the placeholder. However, it does not mention whether the replacement is in-place, what happens if the placeholder is missing, or any side effects like formatting preservation.

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?

Single sentence that is front-loaded with the action and clearly communicates the tool's purpose. No extraneous information.

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?

The description covers the main action and all parameters are explained in schema. However, without an output schema, it would be helpful to know the return value (e.g., success, count of replacements). But given the low complexity, it is mostly complete.

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%, but the description adds value by explaining how the parameters work together: 'replaces every occurrence' and provides an example placeholder format. This contextualizes the parameters beyond their individual schema descriptions.

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 clearly states the verb 'replaces', the resource 'placeholder string in a Google Document', and the action 'with provided text'. It specifies an example placeholder format ({{email_draft}}). This distinguishes it from siblings like append_text which appends to the end, and create_document which creates new documents.

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 implies usage when placeholders need replacement but does not explicitly state when to use this tool over siblings like append_text or read_document. No guidance on when not to use it or alternatives.

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