table_sizes

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

No annotations are provided, so the description carries the burden. It discloses sorting behavior and the inclusion of data/indexes/total, which is useful, but it does not mention whether this is read-only, whether it requires special permissions, whether it includes temporary/metadata tables, or whether it scans all schemas. A read-only report tool without annotations should state safety and scope assumptions.

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?

One concise, information-dense sentence with zero filler. It front-loads the main purpose, specifies scope, and states the sort order.

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 simple report tool with one optional parameter and no output schema, the description is mostly complete. However, it lacks a note about scope (current database? all schemas?), whether it is safe/read-only, and how the result set behaves with the limit (top N by total? ties?). These gaps are modest given the tool's simplicity.

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 100%, so the schema already documents the limit parameter. The description adds the default sorting and what sizes are shown, which gives context for the limit parameter, but there is no extra detail such as whether 0 means unlimited or how limit interacts with the sort. Baseline 3 applies; slight credit for the description reinforcing the sort order that makes limit meaningful.

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?

Description uses specific verb 'Show' with resource 'table sizes' and clarifies it includes data, indexes, and total, sorted by total size descending. This clearly distinguishes it from siblings like database_size, row_counts, and table_stats.

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?

The description implies a read-only reporting use case and the sibling list includes alternatives like database_size, row_counts, table_stats, but it does not explicitly state when to choose this tool over those alternatives. The sorting and included sizes hint at its purpose, but there is no explicit when/why guidance.

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