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

Annotations already declare readOnlyHint and closed-world scope, so 'Read-only' is largely redundant but consistent. The description earns credit by disclosing what content the response mirrors (the plugin's proposed actions, subtypes, defaults, gates, existing LCOM rows) — behavior the agent could not otherwise anticipate given there is no output schema. It does not mention failure modes when no model or plugin data is present.

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?

A single dense sentence that front-loads the core comparison ('Reads the open model the way the Eurocode Load Combinations plugin does') and then lists returned content in a scannable order. No filler and no repetition of the title.

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?

With no output schema, the enumeration of returned data is exactly what an agent needs to decide whether to call it. The only gap is the missing link to the apply/undo siblings and to the equivalent CS454 reader, which would complete the workflow picture.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies; the description correctly implies the tool operates on the currently open model with no scoping arguments.

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?

Names a specific verb (reads) and resource (the open model as seen by the Eurocode Load Combinations plugin) and enumerates exactly what is returned: case types, proposed actions/subtypes, bridge type, default scope and factors, tab gates, and existing LCOM combinations. It is clearly a read operation and distinct in spirit from ec_combinations_apply/undo, but it never names those siblings explicitly, so differentiation comes from the 'Reads'/'Read-only' wording rather than a stated contrast.

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: an agent can infer this is the inspection step before ec_combinations_apply or for reviewing existing LCOM tables, but no sentence says when to use it, when not to, or which alternative (e.g. cs454_combinations_read for the UK code path) to prefer. There are no prerequisites or sequencing notes.

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