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

Annotations already cover the safe-read profile (readOnlyHint, idempotentHint, non-destructive), so the description focuses on the non-obvious trait: card edits become mutates on the model and are visible to get_state and explain. This is genuinely useful context an agent cannot infer. It stops short of saying what happens when viewDefinition is absent (error message vs. refusal), which would complete the picture.

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?

Four sentences, front-loaded with purpose followed by sequencing, prerequisite and the alternative. Dense but nearly every sentence earns its place; the viewDefinition sentence could be folded into the prerequisite clause to tighten it slightly.

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?

Given a single required parameter and no output schema, the description covers purpose, prerequisites, side effects, sequencing and the competing tool. An agent needs nothing else to decide between show_model and render_model.

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% and there is only one parameter, so baseline is 4. The description adds a small amount of meaning by scoping the id to a model created with create_model rather than a spec or arbitrary 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 and resource ('Show the user one of this server's models') and pins the output modality ('as an interactive card in the chat'). It explicitly distinguishes itself from the nearest sibling by naming render_model for the spec-without-model case.

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 explicit timing ('Use it after create_model or evolve_spec when the user should see or try the model') and an explicit exclusion with the alternative tool ('To show a spec without creating a model, use render_model instead'). A prerequisite (viewDefinition) is also stated.

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