get_asset_file_size

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description goes further with a real behavioral disclosure: the resolution algorithm (full package name first, then a /Game-only exact-name scan, first hit wins) and the resulting ambiguous_matches field. It also warns about a non-obvious measurement pitfall that no annotation could convey.

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?

Front-loaded with the action and the measurement it produces, then the warning, then alternatives, then the return shape. The anecdote is slightly long, but it is the sentence that justifies the warning and therefore earns its place. Minor redundancy in restating units (bytes, KB, MB) both in prose and in the Returns block.

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?

There is no output schema, and the description compensates fully with an inline Returns block enumerating every field including the optional ambiguous_matches. Combined with the resolution semantics and the misuse warning, an agent has everything needed to call it correctly and interpret 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 coverage is 100%, so the baseline is 3, but the description adds meaning beyond the schema: it explains the resolution precedence order and the first-hit-wins/ambiguous_matches outcome, and that only the full package name reaches outside /Game. It does not restate the parameter's own description, so the added value is real.

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: 'Read the ON-DISK size of an asset's .uasset in bytes, KB and MB, plus the absolute file path'. It explicitly separates itself from content/integrity tools (get_data_table_info, read_data_table_row_complex, get_asset_dependencies) and in-memory tools (get_asset_memory_usage). It does not, however, differentiate itself from the very similar sibling get_asset_disk_size, leaving an ambiguity an agent cannot resolve from this text alone.

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 use case ('the measurement for a disk-budget question'), an explicit counter-case with a concrete failure anecdote (a DataTable that grew 5 KB lost 46 of 48 references), and named alternatives for both content measurement and memory cost. Nothing is left to inference about when this tool is the right pick.

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