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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), so the description's value is in the return-shape disclosure: one line per table with name/description/first columns without `tables`, versus full column lists, types, foreign keys and notes with `tables`. That is meaningful behavior beyond the annotations, though it says nothing about pagination or failure modes.

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?

Three tight sentences, no filler, with the purpose, the two operating modes, and the call trigger front-loaded in that order. Every sentence earns its place.

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 single optional-parameter introspection tool with no output schema, the description supplies both the call condition and the full shape of both return modes. Nothing an agent needs before invoking it or interpreting the result is missing.

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 is 3, but the description goes further by explaining what the parameter changes semantically: omitted returns a condensed summary, supplied returns full detail. The max-20 limit lives in the schema rather than the description.

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 uses a specific verb+resource ('describe the workspace's data tables') and immediately scopes it to readable tables, distinguishing it from write-side siblings like dispatch_query or run_sql. The two-mode behavior is stated up front so the agent knows what it gets.

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?

It gives an explicit call condition ('Call this before writing SQL'), which is decisive usage guidance. It stops short of naming an alternative tool or stating when not to use it, so it isn't a full 5.

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