describe_entity_type

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

With no annotations provided, the description carries the full burden and does so: read-only with no persistence side effects, InvalidParams error when no active schema exists, and a detailed scope behavior note (prefers user scope, ERR_SCHEMA_SCOPE_MISMATCH on explicit user_specific: false). This is far more than the annotations would have 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?

Purpose and return shape are front-loaded, then usage, repair flow, errors, and scope. Dense and mostly earning its place, but the final scope note drifts into update_schema_incremental's behavior and ERR_SCHEMA_SCOPE_MISMATCH handling, which is more about a sibling than this call.

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?

No output schema exists, so spelling out the returned keys (field_summary, required_fields, schema_version, schema_definition) is exactly the right compensation. Errors, scope, and repair path are all covered; an agent has everything needed to call and act on the result.

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 0% across 2 bare parameters (user_id, entity_type), so the description must compensate. It implies entity_type as the target and hints at session-user scoping, but never explains the user_id parameter's role or how scope resolution actually works for it. Partial compensation only.

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+resource ('Return the full active schema for one entity_type') and enumerates exactly what comes back (field_names, field_summary, required_fields, schema_version, schema_definition). It is immediately distinguishable from schema-adjacent siblings like list_entity_types and register_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?

Gives an explicit when-to-use ('Call this before store when you know the entity_type but not its declared field shape'), a concrete repair trigger (unknown_fields_count > 0), and named alternatives with conditions (list_entity_types to discover, register_schema/update_schema_incremental only when no declared field fits). Nothing is left to inference.

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