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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the agent knows this is a non-idempotent additive write. The description adds value-format constraints, but it says nothing about duplicate-record risk (despite non-idempotency), partial failure behavior, or what happens when an invalid field/value is supplied.

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?

Two sentences, zero waste, with the core action front-loaded and the formatting rules following immediately. Nothing is repeated from the tool name or schema.

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 3-parameter, fully-described schema with no output schema, the definition covers the main ambiguity an agent faces: how to format values of each type via the nested 'fields' object. The remaining gap is the lack of any indication of what the call returns or how errors/validation failures surface.

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 would be 3, and the description genuinely rises above it by explaining what a 'fields' value should look like for each field type: ISO dates, one-of-the-options for choices, and linked record ids for relations. That is real semantics the schema's 'Field id or label -> value' does not convey.

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 opens with a specific verb+resource ('Add a new record to a collection'), which cleanly separates it from the read-oriented siblings (get_record, list_records, search_records, list_apps, describe_app). It does not name an alternative or state that this is the only write path, so it stops short of explicit sibling differentiation.

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?

Usage is only implied: the word 'Add' makes clear this is the creation path, and the sentence on value formats tells the agent what input is expected. There is no statement of prerequisites (e.g., that the collection must exist or that required fields must be supplied) and no mention of when to prefer this over other operations.

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